Spring fastener with highly improved lever/angle pulling force

ABSTRACT

A spring fastener characterized by a structure having a cavity in which the rib of a first part, such as a plastic panel for example, like a pillar, may be engaged, and is also suitable to be engaged reversibly in a slot of second part, such as a metal sheet for example, like the frame of a car. The spring fastener comprises engagement springs having a peak, engagement regions and-side cuts in the vicinity of the peak, preferably within the engagement regions. The side-cuts, of preferably triangular shape, increase considerably the lever/angle pulling force (pulling force applied on the first part and away from the spring fastener, in order to separate the first part from a second part connected together with the spring fastener). It is highly preferable that the fastener comprises barbs with inwardly bent front ends, and that the engagement regions further have hindrance portions, the combination of which highly improves the balance of insertion to removal ratio.

RELATED APPLICATIONS

This application claims priority of provisional patent application60/520/807, filed Nov. 17, 2003, which is incorporated herein byreference in its entirety.

FIELD OF THE INVENTION

This invention relates to spring fasteners characterized by a structurehaving a cavity in which an extension or rib of a first part, such as aplastic panel for example, may be engaged, and they are also suitable tobe engaged reversibly in a slot of second part, such as a metal sheet orthe frame of a car for example. The invention also pertains an assemblyof the first and the second part as connected to each other through thefastener, as well as vehicles comprising such assemblies.

BACKGROUND OF THE INVENTION

A number of fasteners have been used in the past for securing one objecton another object, as for example, securing an article such as forexample a plastic sheet on a metal or other rigid plastic sheet.However, the fasteners of the type, which are improved by the advancesof the present invention, and being used presently, have a rather lowratio of insertion force to removal force. In other words, they requireconsiderable force to be inserted into a slot in order to provideadequate removal resistance in order to be removed from the slot. Thisis ergonomically inferior performance, and the operators may suffermiscellaneous ailments, while productivity is also considerablyundermined. In addition the fasteners of the present state in the artsuffer from rather inferior Lever/Angle Pulling force.

Lever/Angle pulling force is defined as the force required to separateone part from another part connected with a fastener by pulling saidparts apart, not straight away form each other, but sideways from eachother, as will be described in more detail hereinbelow.

One of the major objectives of the present invention is to providefasteners of considerably higher Lever/Angle pulling force than thefasteners of the present state in the art.

Recently, a fastener has been disclosed in U.S. Pat. No. 6,718,599 B2,which is incorporated herein by reference, characterized byergonomically balanced removal to insertion force ratio. However, evenin this case, the Lever/Angle pulling force is relatively low.

Examples of other state in the art fasteners are disclosed in U.S. Pat.No. 6,381,811 (Smith et al.), U.S. Pat. No. 6,353,981, U.S. Pat. No.6,074,150 (Shinozaki et al.), U.S. Pat. No. 5,987,714 (Smith); U.S. Pat.No. 5,887,319 (Smith); U.S. Pat. No. 5,542,158 (Gronau et al.); U.S.Pat. No. 5,422,789 (Fisher et al.), U.S. Pat. No. 5,373,611 (Murata);U.S. Pat. No. 5,314,280 (Gagliardi); U.S. Pat. No. 5,095,592(Doerfling); U.S. Pat. No. 4,701,984 (Wyckoff), U.S. Pat. No. 4,792,475(Bien); U.S. Pat. No. 4,683,622 (Ohelke); U.S. Pat. No. 4,609,170(Schnabl); U.S. Pat. No. 4,245,652 (Kelly et al.); U.S. Pat. No.3,864,789 (Leitner); U.S. Pat. No. 3,673,643 (Kindell); U.S. Pat. No.3,525,129 (Holton); U.S. Pat. No. 2,825,948 (Parkin); U.S. Pat. No.2,607,971 (Bedford, Jr.); U.S. Pat. No. 2,542,883 (Tinnerman); U.S. Pat.No. 2,329,688 (Bedford, Jr.); U.S. Pat. No. 2,322,656 (Murphy), amongothers.

U.S. Pat. No. 5,919,019 (Fisher) provides fasteners which can only bepermanently installed into a slot; they can only be inserted but notextracted without damage to parts of the fastener. The major engagementis performed by spring strips, while frictional portions of the fastenerpass through the slot with at most slight compression, and immediatelyafter the insertion of the fastener they are located in slightly spacedor barely contacting relation with the edges of the slot. They are onlyactivated for engagement after the insertion of a bolt into a hole atthe base plate. Thus, the profound effect of the increased removal toinsertion ratio (explained in detail hereinbelow) is not recognized,mentioned, or implied. Thus, the intentionally provided distance of thefrictional portions away from the edges of the slot by Fisher, duringinsertion and before use of the bolt, teaches actually away from theinstant invention, which recognizes and takes full advantage of theincreased removal to insertion ratio by an engagement region having ahindrance portion. As a matter of fact, if the engagement surfaces ofthe instant invention were located in slightly spaced or barelycontacting relation with the edges of the slot, no engagement at allwould take place upon insertion of the fastener of this invention intothe slot.

U.S. Pat. No. 6,141,837 (Wisniewski) describes a spring fastenercomprising bulbous and outwardly projecting portions, which assist inpreventing withdrawal of the clip and associated molding from anaperture of a vehicle frame. However, “bulbous projections” arenecessarily voluminous, take most of the space between the “reversebents”, and unless they are manufactured within tight tolerances withregard to the thickness of the frame, the “base plates” do not sit onthe frame (see also the Figures), rendering the structure unstable.

U.S. Pat. No. 6,203,240 B1 (Hironaka et al.), U.S. Pat. No. 5,129,768(Hoyle et al.), U.S. Pat. No. 5,092,550 (Bettini), U.S. Pat. No.4,981,310 (Belissaire), U.S. Pat. No. 4,712,341 (Harris, Jr. et al.),U.S. Pat. No. 4,595,325 (Moran et al.), U.S. Pat. No. 4,431,355(Junemann), U.S. Pat. No. 4,133,246 (Small), and U.S. Pat. No. 2,424,757(F. Klump, Jr.) are directed to plastic or metal fasteners which aredesigned to be just inserted into the slot of a panel, but not extractedwithout damage to the fastener (if such extraction would be attemptedfrom the front side; the side from which the fastener is inserted intothe panel, since the back part of the panel is not reachable in thecases, wherein such types of fasteners are used).

None of the above disclosures of the present state in the art providesatisfactory Lever/Angle pulling force.

SUMMARY OF THE INVENTION

As aforementioned, this invention relates to spring fastenerscharacterized by a structure having a cavity in which the rib of a firstpart, such as a plastic panel for example, may be engaged, and they arealso suitable to be engaged reversibly in a slot of second part, such asa metal sheet or the frame of a car for example. The invention alsopertains an assembly of the first and the second part as connected toeach other through the fastener, as well as vehicles comprising suchassemblies. The spring fasteners of the present invention arecharacterized by a Lever/Angle pulling force, which is considerablyhigher than that characterizing spring fasteners of the present state inthe art.

A very unexpected increase in Lever/Angle pulling force is attained byforming a side-cut section, especially at least partially bentoutwardly, disposed in critical positions of the spring fastener, aswill described in more detail hereinbelow.

Outwardly means away from the fastener.

More particularly, this invention pertains a spring fastener comprisinga first side and a second side opposite the first side, the first sideconnected to the second side thereby forming a U-shaped structure havinga cavity between the first side and the second side, a bottom portionwherein the first side and the second side are connected, and a topportion, the first side comprising a first spring, the first springconnected to the first side in the vicinity of the bottom portion, thesecond side comprising a second spring, the second spring connected tothe second side in the vicinity of the bottom portion, each of the firstand second engagement springs comprising a peak, a free end in thevicinity of the top portion, and an engagement region between the peakand the front end, at least one spring further having a side-cut sectionor notch, preferably in the vicinity the respective peak, the side-cutsection or notch oriented substantially parallel to the peak. It ispreferable, however, that each spring has two side-cut sections, oneopposite to the other.

The side-cut sections or notches have an upper edge and a lower edge. Itis highly preferable that at least one of the lower edges, and even morepreferable that all lower edges are at least partially bent outwardly.

This invention further pertains an assembly comprising:

-   -   a spring fastener comprising a first side and a second side        opposite the first side, the first side connected to the second        side thereby forming a U-shaped structure having a cavity        between the first side and the second side, a bottom portion        wherein the first side and the second side are connected, and a        top portion, the first side comprising a first spring, the first        spring connected to the first side in the vicinity of the bottom        portion, the second side comprising a second spring, the second        spring connected to the second side in the vicinity of the        bottom portion, each of the first and second engagement springs        comprising a peak, a free end in the vicinity of the top        portion, and an engagement region between the peak and the front        end, at least one spring further having a side-cut section,        preferably in the vicinity the respective peak, the side cut        section oriented substantially parallel to the peak, and having        an upper edge and a lower edge;    -   a first part comprising a rib inserted into the cavity of the        spring fastener and engaged to the first and second barbs;        and/or    -   a second part comprising a slot, the slot having a width and        edges, the fastener being disposed in the slot in a manner that        the edges of said slot are engaged to the engagement regions of        the spring fastener.

In addition, this invention is related to a vehicle which comprises anassembly, the assembly comprising vehicle comprising an assembly, theassembly comprising:

-   -   a spring fastener comprising a first side and a second side        opposite the first side, the first side connected to the second        side thereby forming a U-shaped structure having a cavity        between the first side and the second side, a bottom portion        wherein the first side and the second side are connected, and a        top portion, the first side comprising a first spring, the first        spring connected to the first side in the vicinity of the bottom        portion, the second side comprising a second spring, the second        spring connected to the second side in the vicinity of the        bottom portion, each of the first and second engagement springs        comprising a peak, a free end in the vicinity of the top        portion, and an engagement region between the peak and the front        end, at least one spring further having a side-cut section,        preferably in the vicinity the respective peak, the side cut        section oriented substantially parallel to the peak, and having        an upper edge and a lower edge;    -   a first part comprising a rib inserted into the cavity of the        spring fastener and engaged to the first and second barbs; and    -   a second part comprising a slot, the slot having a width and        edges, the fastener being disposed in the slot in a manner that        the edges of said slot are engaged to the engagement regions of        the spring fastener.

It is preferable that the fastener comprises hindrance portion withinthe engagement region, and more preferable that the side-cut section isdisposed within the engagement region. It is further highly preferablethat the side-cut section has a triangular shape.

The spring fastener of the present invention may further comprise arecess within the engagement region, in the vicinity of the top end.

The hindrance portion may have any suitable structure, which hinders toa desired degree the removal of the spring fastener from the slotdescribed above. It is preferable, however, that said hindrance portioncomprises one structure selected from ripple, side rib, upward solidbent extension parallel to the peak and the optional recess, knurledregion, bent teeth, each having a depth, a bump or bulbous formation,and a combination thereof.

The presence of a single ripple in the vicinity of the peak is morepreferable according to this invention, and it is even more preferablethat the ripple has a back side with a curvature of a graduallydecreasing slope. Preferably, the gradually decreasing slope has theshape of an arc in the range of 50-70 degrees with a radius in the rangeof 0.03-0.05 mm.

More details regarding preferred configurations of engagement regionsare described in Non-provisional patent application Ser. No. 10/164,963,filed Jun. 7, 2002, and its respective Patent Application Publication US2002/0194710 A1, Pub. Date Dec. 26, 2002, both of which are incorporatedherein by reference.

It is further preferable that the spring fastener of this inventionfurther comprises first barbs and second barbs being cut portions of therespective first and second side of the spring fastener, originatingfrom the vicinity of the top portion of said spring fastener anddirected toward the bottom portion the spring fastener, the first barbsand the second barbs comprising respective first back sections and firstfront sections, the first sections being bent portions of the first backsections, and second back sections and second front sections, the secondfront sections being bent portions of the second back sections.

The barbs are preferably selected from a group consisting essentiallyof:

-   -   first barbs being outer barbs and second barbs being inner        barbs;    -   first barbs being outside outer barbs and second barbs being        inside outer barbs; and    -   first barbs being inner barbs and second barbs being inner        barbs.

It is preferable that the barbs which are cut from their respectiveside, are flexible, and bent in the vicinity of their respective frontend as described for example in U.S. Pat. No. 6,279,207 B1, which isincorporated herein by reference, and more particularly in FIG. 1A ofsaid patent, with an angle of bent in the range of 5-25 degrees.

The barbs are considered to be flexible if they do not cause the widthW3 (FIG. 1B) to increase more than 30%, preferably 20%, and morepreferably 10%, when the rib 46 is inserted into the cavity 19 of thefastener 10 (FIG. 4A), and provided that the first object 46 isadequately hard to hinder the barbs 36 from substantially digging intoit.

Regarding the outside outer barbs, it is preferable that their frontpoints are at a distance from the second side smaller than the thicknessof the material from which the spring fastener was made. This is toavoid interconnection of the fasteners, when said fasteners are storedin bulk.

The barbs may have variable width along their length, or they may havesubstantially the same width along their length. Further, the frontpoints of the barbs may be toothed.

More details regarding our preferred bent barbs are also described inU.S. Pat. Nos. 6,279,207 B1 and 6,691,380 B2, both of which areincorporated herein by reference.

The spring fastener of the instant invention may further comprise amolded elastic body at least under the top portion of said springfastener for sealing purposes. Such arrangements are disclosed in U.S.Pat. No. 6,353,981 B1, which is incorporated herein by reference. Othersealing arrangements are also included in the instant invention, asdescribed for example in U.S. Pat. No. 6,527,471 B2, which is alsoincorporated herein by reference.

In another embodiment, the spring fastener of the instant invention mayfurther comprise:

-   -   an elastic body comprised of at least a gasket, the gasket        extending away from the cavity in the vicinity of the top        portion of the fastener and enclosing at least partially the        cavity; and    -   a casing surrounding at least partially the spring fastener        under the top portion, except at least the engagement section of        each engagement spring, the casing also at least partially        surrounding the cavity and such portion of the elastic body        which at least partially encloses the cavity;    -   wherein the casing has lower ultimate elongation, higher Shore        hardness, and higher shear strength than the elastic body. Thus,        preferably the casing is substantially non-elastic.

Such arrangements are disclosed in U.S. Pat. Nos. 6,381,811 B2,6,497,011 B2, 6,527,471 B2, and 6,648,547 B2, all of which isincorporated herein by reference.

According to the present invention, any embodiments of fastenersdescribed above and their equivalents may be used in any assembly inwhich the first part and/or the second part are connected with thefastener, as well as in any vehicle comprising such an assembly or sucha fastener or its equivalents.

DESCRIPTION OF THE DRAWING

The reader's understanding of practical implementation of preferredembodiments of the invention will be enhanced by reference to thefollowing detailed description taken in conjunction with perusal of thedrawing figures, wherein:

FIG. 1 illustrates a perspective view of a spring fastener according toa preferred embodiment of the present invention, wherein the engagementregions of the first and second springs have side-cut sections ornotches in the vicinity of the bent.

FIG. 1A 1 illustrates a perspective view of a spring fastener accordingto another preferred embodiment of the present invention, wherein thehindrance portion comprises a single-sided ripple and bent barbs, andthe engagement regions of the first and second springs have side-cutsections or notches in the vicinity of the bent.

FIG. 1B shows a side view of the spring fastener of FIG. 1A.

FIG. 1C illustrates a perspective view of a spring fastener according toanother preferred embodiment of the present invention, wherein the loweredges of the side-cut sections or notches are at least partially bentoutwardly.

FIG. 2 illustrates a perspective view of a spring fastener according toanother preferred embodiment of the present invention, wherein thehindrance portion comprises one two-sided ripple and bent barbs, and theengagement regions of the first and second springs have side-cutsections or notches in the vicinity of the bent.

FIG. 3A illustrates side view of an engagement spring, wherein thehindrance portion comprises a single-sided ripple, and the engagementregions have side-cut sections or notches in the vicinity of the bent.

FIG. 3B illustrates a side view of an engagement spring, wherein thehindrance portion comprises one two-sided ripple, and the engagementregions have side-cut sections or notches in the vicinity of the bent.

FIG. 3C illustrates a side view of an engagement spring, wherein thehindrance portion comprises two two-sided ripples, and the engagementregions have side-cut sections or notches in the vicinity of the bent.

FIG. 3D illustrates a side view slice of an engagement spring, whereinthe hindrance portion comprises three two-sided ripples, and theengagement regions have side-cut sections or notches in the vicinity ofthe bent.

FIG. 4 illustrates two parts, which can be connected with the fasteneraccording to the present invention.

FIG. 4A illustrates the side view of the fastener of FIG. 1A and a crosssectional slice of the rib of a first part, such as a panel or anautomotive pillar, for example, inserted into the cavity of thefastener.

FIG. 4B illustrates the same elements shown in FIG. 4A after insertionof the fastener into the slot of a second part, such as the frame of anautomobile for example.

FIG. 4C illustrates a partial cross section of the second part of FIG.4B and the edges of the slot in relation with the engagement regions ofthe engagement springs of the fastener.

FIG. 5 illustrates a detailed diagram of a ripple in the hindranceportion according to preferred embodiments of the instant invention.

FIG. 5A illustrates a detailed diagram of a single-sided ripple having aback side in the form of a curvature in the hindrance portion accordingto a highly preferred embodiment of the instant invention.

FIG. 6 illustrates a stamped fastener before final formation accordingto another embodiment of the present invention, wherein the fastenercomprises outer and inner barbs, as well as relief portions in thevicinity of the bottom of the fastener.

FIG. 6A illustrates a side view of the fastener of FIG. 6 after finalformation.

FIG. 7 illustrates a stamped fastener before final formation accordingto another embodiment of the present invention, wherein the fastenercomprises outside outer barbs on the first side and inside outer barbson the second side.

FIG. 8 illustrates a stamped fastener before final formation accordingto another embodiment of the present invention, wherein the fastenercomprises only inner barbs.

FIG. 9 illustrates a stamped fastener before final formation accordingto another embodiment of the present invention, wherein the fastenercomprises upper and lower outer and inner barbs.

FIG. 10 illustrates a stamped fastener before final formation accordingto another embodiment of the present invention, wherein the fastenercomprises two engagement springs per side of the fastener, and only oneupper and one lower barb per side.

FIG. 11 illustrates a stamped fastener before final formation accordingto another embodiment of the present invention, wherein the barbs haveuniform width along their length.

FIG. 12 illustrates a stamped fastener before final formation accordingto another embodiment of the present invention, wherein the barbs haveuniform width along their length, and they are toothed at their frontends.

FIG. 13 illustrates a cross-sectional slice of the middle portion of aspring fastener, according to another embodiment of the instantinvention, wherein a molded elastic body 54 is disposed at least underthe top portion of said spring fastener.

FIG. 14 is a perspective view of a fastener, according to still anotherembodiment of the instant invention, wherein the lower portion of thefastener is covered by a casing, while an elastic body is disposed inthe vicinity of the top portion and encloses the cavity, at leastpartially.

DETAILED DESCRIPTION OF THE INVENTION

As aforementioned, this invention relates to spring fastenerscharacterized by a structure having a cavity in which the rib of a firstpart, such as a plastic panel for example, like a pillar for example,may be engaged, and they are also suitable to be engaged reversibly in aslot of second part, such as a metal sheet for example, like the frameof a car for example. The invention also pertains an assembly of thefirst part connected to the fastener, the first and the second partconnected to each other through the fastener, as well as vehiclescomprising such assemblies.

More particularly, as better shown in FIGS. 1, 1A and 1B, the inventionpertains a spring fastener 10 comprising a first side 12 and a secondside 14 opposite the first side 12. The first side 12 is connected tothe second side 14 forming a U-shaped structure which has a cavity 19between the first side 12 and the second side 14. The fastener 10 alsohas a bottom portion 16, wherein the first side 12 and the second side14 are connected. It further has a top portion 18 a and 18 b(collectively 18).

In all cases, numerals referring to the first side 12 contain the letter“a”, while numerals referring the second side 14 contain the letter “b”.The same numerals without the letters “a” or “b”, refer collectively tothe respective elements of both sides.

The first side 12 comprises a first engagement spring 20 a, which isconnected to the first side 12 in the vicinity of the bottom portion 16.

The second side 14 comprises a second engagement spring 20 b, which isconnected to the second side 14, also in the vicinity of the bottomportion.

Each of the first and second engagement springs 20 a and 20 b maypreferably, but not necessarily, have a first and second recess, 24 aand 24 b, respectively, as shown in FIGS. 1A and 1B, and a first andsecond free end, 22 a and 22 b, respectively, in the vicinity of the topportion 18 (18 a and 18 b, respectively). Each spring also comprises afirst and a second peak, 26 a and 26 b, respectively, and a first andsecond engagement region, 28 a and 28 b, respectively.

Preferably, within the engagement region, and more preferably in thevicinity of the peaks 26, there are side-cut sections 8 a and 8 b(collectively 8), preferably of triangular shape, which render thelever/angle pulling force considerably higher than it would have been intheir absence. Each of the side-cut sections or notches 8 has an upperedge 7 (7 a and 7 b), and a lower edge 9 (9 a and 9 b). It is highlypreferable that the lower edges 9 (9 a and 9 b) are at least partiallybent outwardly, as better illustrated in FIG. 1C.

As aforementioned, lever/angle pulling force is defined as the forcerequired to separate one part from another part connected with afastener by pulling said parts apart, not straight away form each other,but sideways from each other.

It is highly preferable also, that the engagement regions 28, furthercomprise a first and second hindrance portion, 29 a and 29 b,respectively, between the bents 26 and the front ends 22.

The hindrance portions provide increased removal force, when thefastener 10 is pulled by a rib or extension 46 (FIG. 4B) of a first part44 (FIG. 4) engaged to the first and second barbs, 36 a and 36 b,respectively, after the fastener 10 has been inserted into a slot 50 ofa second part 48 (FIG. 4), the slot 50 having a slot width W2 (FIGS. 4and 4C) and edges 51 (FIG. 4C) on which edges the engagement regions 28a and 28 b are engaged. The removal force is measured by pulling rib 46of the first part 44 straight away from the second part 48 in thevicinity of point F1.

The increased removal force is due to the hindrance portions 29 a and 29b (FIG. 4C), which in this particular case comprise single ripples withonly back sides 34, as it will be explained at a later point in moredetail. According to this invention, the engagement portions 28 a and 28b and the hindrance regions 29 a and 29 b are required to be such thatthe fastener 10 can be extracted from the slot 50 when pulled by the rib46 without damage to said fastener 10, and with a higher force than aforce required in the absence of the hindrance portions 29 a and 29 b.

The lever/angle pulling force is measured by pulling the first part 44apart from the second part 48, not straight away, but sideways from eachother, that is for example by pulling the first part 44 from a point F2away from the rib 46, such as the edge 45 for example of the first part44, such as an automotive pillar for example.

In different applications, the exact position of point F2 may bedifferent, as well as the required increase in lever/angle force by theuse of the side-cut sections.

The first side 12 also comprises first barbs 36 a, which in the caseshown in FIGS. 1A and 1B are outer barbs, since they are disposed in anouter portion of the first side 12. The barbs 36 a have first front ends38 a. In the particular cases of FIGS. 1A and 1B, the first barbs 36 aare bent inwardly in the vicinity of the front ends 38 a, according to ahighly preferred embodiment of the instant invention.

The second side 14 comprises second barbs 36 b, which in the case ofFIGS. 1A and 1B are inner barbs, since they are disposed in an innerportion of the second side 14. The second barbs have second front ends38 b. In this particular case of FIGS. 1A and 1B the second barbs 36 bare also bent inwardly in the vicinity of the front ends 38 b, accordingto a highly preferred embodiment of the instant invention.

In the case of FIG. 1, the barbs 36 a and 36 b are straight.

This invention further pertains an assembly 11, as better shown in FIG.4B, comprising a spring fastener as described above or in theembodiments and their equivalents presented hereinbelow, and a firstpart 44 (FIG. 4) comprising a rib 46 (FIG. 4A) inserted into the cavity19 of the spring fastener 10 and engaged to the first and second barbs36 a and 36 b.

Further, this invention further pertains an assembly 1, as better shownin FIG. 4B, comprising a spring fastener as described above or in theembodiments presented hereinbelow; a first part 44 (FIG. 4) comprising arib 46 (FIG. 4A) inserted into the cavity 19 of the spring fastener 10and engaged to the first and second barbs 36 a and 36 b; and a secondpart 48 (FIGS. 4 and 4B) comprising a slot 50, which slot 50 has a widthW2 and edges 51 (FIG. 4C), so that the edges 51 of said slot are engagedto the engagement regions 28 a and 28 b of the spring fastener 10. Inthis case also, the requirement exists that by pulling the rib 46, thefastener 10 is extracted from the slot 50 without damage to the fastener10, and with a higher force than a force required in the absence of thehindrance portions 29 a and 29 b.

In addition, this invention is related to a vehicle which comprises anassembly 11, as described above.

In operation of the above embodiments, the spring fastener 10 of thepresent invention is intended to connect a first part, such as a panel44 for example, which panel may have a rib 46, with a second part, suchas a frame 48 of a car for example, having a slot 50, as illustrated inFIG. 4.

The rib 46 of the panel 44 is preferably first inserted into the cavity19 of the fastener 10 (see FIG. 4A), where, it is secured by barbs 36 aand 36 b. Then, the fastener 10, which has been secured on the extension46 of the panel 44, is inserted into the slot 50 of the frame 48, asbetter shown in FIG. 4B. However the sequence inserting the fastener maybe the opposite.

In this manner, the first part, exemplified by panel 44, has beenconnected on the second part, exemplified by frame 48, through thefastener 10 of the instant invention.

In most practical applications, the length Le (see FIG. 4A) of theengagement regions 28 is not higher than 2-4 mm, while the thicknessT_(f) of the frame 48 (see FIG. 4B) may vary in most occasions in therange of 0.5 to 2 mm. This fact makes it rather difficult to form largehindrance portions. Thus, The “bulbous projections” suggested by U.S.Pat. No. 6,141,837 (Wisniewski) are necessarily too bulky andvoluminous, take most of the space between the “reverse bents”(engagement regions between the peak and the recess in the case of theinstant invention), and unless they are manufactured within tighttolerances with regard to the thickness of the frame (which in practicemay vary considerably), the “base plates” (top portions in the case ofthe present invention) do not sit on the frame (see also Wisniewski'sFigures), rendering the structure considerably unstable.

According to this invention, and particularly for ergonomic purposescombined with practical aspects, it is highly preferable that the forceto insert the rib of the first part into the cavity of the springfastener should be less than 40 lbs, preferably less than 15 lbs, andeven more preferably less that 10 lbs; the force to insert the springfastener into the slot should be less that 30 lbs, preferably less than15 lbs, and even more preferably less than 10 lbs; and the force toextract the spring fastener from the slot should be in the range of30-100 lbs, and preferably in the range of 50-70 lbs.

It was unexpectedly found by the inventors that in order to achieve theabove results, the hindrance portions should comprise rather minuteelements, and not the huge structural components disclosed in the art.Such huge structural components render respective fasteners to beirreversibly inserted into slots. Any attempt to extract these fastenersfrom the side of the panel that they were inserted would result indestruction of the fasteners.

According to this invention, the hindrance portions 29 a and 29 b maycomprise minute elements, such as ripples, upward solid bent extensionsparallel to the peaks and the recesses, knurled regions, bent teeth,each having a depth, the depth of which does not exceed preferably 0.2mm, and more preferably 0.1 mm. Any person of ordinary skill in the artwould not expect that elements having such minute depths would have suchgreat impact in force balances as the aforementioned ones.

The depth for any element is substantially defined in the same manner asdefined at a later point for the ripples.

Although this invention includes any structure which satisfies theclaims, such as for example upward solid bent extensions parallel to thepeaks and the recesses, knurled regions, bent teeth, as described in atleast one of the provisional patent application 60/301,364, filed Jun.25, 2001, 60/327,814, filed Oct. 9, 2001, and 60/353,515, filed Feb. 1,2002, U.S. Pat. Nos. 6,718,599 B2, and 6,745,440 B2, all of which areincorporated herein by reference, and as long as their depth does notexceed 0.2 mm, the most preferable configuration is one that comprisesat most three ripples having a preferable depth not exceeding 0.2 mm,and more preferably not exceeding 0.1 mm. It is more preferable that thehindrance portion comprises not more than two ripples, and even morepreferable one ripple. Structures with one to three two-sided ripples 30are shown in FIGS. 3B to 3D, respectively.

FIG. 2 illustrates a spring fastener 10 according to this invention,wherein the hindrance portion 29 comprises one two-sided ripple 30 andbent barbs 36.

The most efficient and effective case, however, according to thisinvention, is the use of only one single-sided ripple 30, as shown forexample in FIGS. 1A and 3A.

The operation of these embodiments is substantially the same as theoperation of the previous embodiments.

It is preferable that each ripple 30 is in the form of a depression, asbetter shown in FIG. 5. The depression has a deepest part Z, a frontside 32, a back side 34, and a width W1. The hindrance portion 29 has asurface E, and the depth D of each ripple 30 is defined as the distancebetween the surface E of the hindrance portion 29 and the deepest part Zof the respective ripple 30.

For better performance, the ripple width is larger than the depth of theripple, and preferably the ripple width is at least twice the size ofthe depth of the ripple. The ripple width is preferably in the range of0.1 to 0.5 mm and the ripple depth is in the range of 0.01 to 0.1 mm, asaforementioned.

In a preferred embodiment, the back side 34 of the ripple 30 issubstantially linear and has a slope S in the range of 15 to 30 degreeswith regard to the general plane of the surface E of the hindranceportion 29, and it is also preferable that the front side 32 has ahigher slope than the back side. The slope of the front side is measuredin the same manner as the slope of the back side. Thus, if the frontside 32 is substantially perpendicular to the surface E, the slope issubstantially 0 degrees, while if the front side 32 is substantiallyparallel to the plane of surface E and the continuation of the deepestpart Z, it is substantially 90 degrees.

It is, however, highly preferable that the back side 34 has the form ofa curvature with a gradually decreasing slope. For example, thegradually decreasing slope of back side 34 may have the shape of an arccorresponding to an angle A1, preferably in the range of 50-70 degrees,with a radius R, preferably in the range of 0.03-0.05 mm., as bettershown in FIG. 5A.

This configuration is of extreme importance in most occasions, becauseduring vibrations, the edges 51 of the slot 50 (FIG. 4C) slide smoothlyon the engagement regions 28 as well as the hindrance portions 29 duringoperation, and when they reach the back sides 34 of the single-sidedripples 30 (FIG. 5A), they continue sliding smoothly findingincreasingly higher resistance in a continuous manner, which eliminatesany rattling noises. Such rattling noises would be present in a casethat the edges 51 would hit abrupt obstacles or would suddenly jumpdown, even without hitting such obstacles.

The barbs are preferably selected from a group consisting essentiallyof:

-   -   first barbs 36 a being outer barbs, and second barbs 36 b being        inner barbs, as better shown in FIG. 6 (blank before forming)        and 6A (side view);    -   first barbs 36 a being outside outer barbs, and second barbs 36        b being inside outer barbs, as better shown in FIG. 7 (blank        before forming); and    -   first barbs 36 a being inner barbs, and second barbs 36 b being        inner barbs, as better shown in FIG. 8 (blank before forming).

In operation, the barbs engage on the rib 46 of the first part 44, andwhen an adequate pulling force is applied on the firs part 44, thefastener remains on said first part 44, but is extracted from the slot50.

The spring fastener 10 may also comprise relief openings 42 a and 42 bin the vicinity of the bottom 16 of the spring fastener 10, as bettershown in FIG. 6 (blank before forming). These relief openings facilitatethe insertion of the fastener into the slot 50.

The spring fastener 10 may further comprise additional lower barbs 40 aand 40 b pointing inwardly and originating form the vicinity of thebottom portion 16 of the first side and the second side, respectively,of the fastener 10, as better shown in FIG. 9 (blank before forming).

In another embodiment, better illustrated in FIG. 10 (blank beforeforming), the first side of the spring fastener 10 has only one upperbarb 36 a and one lower barb 40 a, while the second side also has alsoonly one upper barb 36 b and only one lower barb 40 b, in a manner thatthe upper barb of one side faces the lower barb of the other side andvice versa.

The barbs 36 may have variable width along their length, as illustratedin for example in FIGS. 6-10, or they may have substantially the samewidth along their length as better shown in FIG. 11. Further, the frontpoints of the barbs 36 may be toothed, as illustrated in FIG. 12.

Regarding outside outer barbs 36, it is preferable that their frontpoints 38 are at a distance C from the second side 14 smaller than thethickness T of the material from which the spring fastener 10 is made,as better shown in FIG. 1B. This is to avoid interconnection of thefasteners, when said fasteners are stored in bulk.

It is preferable that the barbs are cut from their respective side, areflexible, and bent in the vicinity of their respective front end asdescribed for example in U.S. Pat. No. 6,279,207 B1, which isincorporated herein by reference, and more particularly in FIG. 1A ofsaid patent, with an angle of bent in the range of 5-25 degrees.

It is also preferable that the fastener 10 has a width W3 (FIG. 1B) inthe vicinity of the top portion 18 of the fastener 10, which is at least60%, and more preferably at least 70%, as wide as the slot width W2(FIG. 4C). Thus, it is preferable that the whole fastener complies withthis requirement, or at least a portion in the vicinity of the top. Thisis to avoid reversal of the direction and failure of the barbs 36, whenand if the rib 46 is forcefully pulled away from the second part 48(FIG. 4B).

With respect to the engagement regions 28, it is preferable that theseregions are at least partially wider than the rest of the respectiveengagement springs 20 (see for example FIG. 6).

The more barbs are present, or the more bent their front points are, thestronger the engagement of the rib 46 in the cavity 19. However, in manyoccasions it is desirable that this engagement is not so strong so as todestroy the integrity of the fastener or the rib, when an adequate forceis applied to separate the fastener 10 from the rib 46.

The spring fasteners 10 of the instant invention may have two engagementsprings 20 at the edges of each side instead of one engagement spring 20in substantially the middle portion of each side (see for Example FIG.10).

The spring fastener 10 of the instant invention may further comprise amolded elastic body 54 at least under the top portion 18 of said springfastener 10, as better shown in FIG. 13. Such arrangements are disclosedin U.S. Pat. No. 6,353,981 B1, which is incorporated herein byreference.

The operation of this embodiment is similar to the operation of thepreviously described embodiments with the difference that the elasticbody provides moderate sealing properties to the fastener when thefastener is inserted into the slot.

In another embodiment, the spring fastener of the instant invention mayfurther comprise:

-   -   an elastic body 54 comprised of at least a gasket 56, the gasket        56 extending away from the closed cavity 19 in the vicinity of        the top portion 18 of the fastener 10 and enclosing at least        partially the cavity 19; and    -   a casing 58 surrounding at least partially the spring fastener        under the top portion 18, except at least the engagement region        28 of each engagement spring 20, the casing 58 also at least        partially surrounding the cavity 19 and such portion of the        elastic body 54 which at least partially encloses the cavity;    -   wherein the casing 58 has lower ultimate elongation, higher        Shore hardness, and higher shear strength than the elastic body        54;    -   as better shown in FIG. 14.

The presence of lips 60 improves considerably the sealing properties ofthe elastic body.

Such arrangements are also disclosed in U.S. Pat. No. 6,381,811 B2,which is incorporated herein by reference.

The operation of this embodiment is similar to the operation of thepreviously described embodiments with the difference that thecombination of the elastic body 54 with the casing 58 provideoutstanding sealing properties to the fastener 10 when the fastener 10is inserted into the slot 50, and the casing itself facilitates theinsertion of the fastener 10 into the slot 50.

According to the present invention, any embodiments of fastenersdescribed above and their equivalents may be used in any assembly inwhich the first part and the second part are connected with thefastener, as well as in any vehicle comprising such an assembly or sucha fastener or its equivalents.

1. A spring fastener comprising a first side and a second side oppositethe first side, the first side connected to the second side therebyforming a U-shaped structure having a cavity between the first side andthe second side, a bottom portion wherein the first side and the secondside are connected, and a top portion, the first side comprising a firstspring, the first spring connected to the first side in the vicinity ofthe bottom portion, the second side comprising a second spring, thesecond spring connected to the second side in the vicinity of the bottomportion, each of the first and second engagement springs comprising apeak, a free end in the vicinity of the top portion, and an engagementregion between the peak and the front end, at least one spring furtherhaving a side-cut section within the engagement region, the side cutsection oriented substantially parallel to the peak and comprising anupper edge and a lower edge.
 2. A spring fastener as defined in claim 1,further comprising a hindrance portion within the engagement region. 3.A spring fastener as defined in claim 1, wherein the side-cut section isdisposed in the vicinity the respective peak.
 4. A spring fastener asdefined in claim 1, wherein the side-cut section has a triangular shape.5. A spring fastener as defined in claim 1, wherein the lower edge is atleast partially bent outwardly.
 6. A spring fastener as defined in claim3, wherein the lower edge is at least partially bent outwardly.
 7. Aspring fastener as defined in claim 1, further comprising a recess inthe vicinity of the top end.
 8. A spring fastener as defined in claim 3,further comprising a recess in the vicinity of the top end.
 9. A springfastener as defined in claim 6, further comprising a recess in thevicinity of the top end.
 10. A spring fastener as defined in claim 2,wherein the hindrance portion comprises one structure selected fromripple, side rib, upward solid bent extension parallel to the peak,knurled region, bent teeth, each having a depth, a bump, and acombination thereof.
 11. A spring fastener as defined in claim 3,wherein the hindrance portion comprises one structure selected fromripple, side rib, upward solid bent extension parallel to the peak,knurled region, bent teeth, each having a depth, a bump, and acombination thereof.
 12. A spring fastener as defined in claim 6,wherein the hindrance portion comprises one structure selected fromripple, side rib, upward solid bent extension parallel to the peak,knurled region, bent teeth, each having a depth, a bump, and acombination thereof.
 13. A spring fastener as defined in claim 10,wherein the hindrance portion comprises a ripple in the vicinity of thepeak.
 14. A spring fastener as defined in claim 11, wherein thehindrance portion comprises a ripple in the vicinity of the peak.
 15. Aspring fastener as defined in claim 12, wherein the hindrance portioncomprises a ripple in the vicinity of the peak.
 16. A spring fastener asdefined in claim 13, wherein the ripple has a back side with a curvatureof a gradually decreasing slope.
 17. A spring fastener as defined inclaim 14, wherein the ripple has a back side with a curvature of agradually decreasing slope.
 18. A spring fastener as defined in claim15, wherein the ripple has a back side with a curvature of a graduallydecreasing slope.
 19. A spring fastener as defined in claim 16, whereinthe gradually decreasing slope has the shape of an arc in the range of50-70 degrees with a radius in the range of 0.03-0.05 mm.
 20. A springfastener as defined in claim 17, wherein the gradually decreasing slopehas the shape of an arc in the range of 50-70 degrees with a radius inthe range of 0.03-0.05 mm.
 21. A spring fastener as defined in claim 18,wherein the gradually decreasing slope has the shape of an arc in therange of 50-70 degrees with a radius in the range of 0.03-0.05 mm.
 22. Aspring fastener as defined in claim 1, further comprising first barbsand second barbs being cut portions of the respective first and secondside of the spring fastener, originating from the vicinity of the topportion of said spring fastener and directed toward the bottom portionthe spring fastener, the first barbs and the second barbs comprisingrespective first back sections and first front sections, the firstsections being bent portions of the first back sections, and second backsections and second front sections, the second front sections being bentportions of the second back sections.
 23. A spring fastener as definedin claim 2, further comprising first barbs and second barbs being cutportions of the respective first and second side of the spring fastener,originating from the vicinity of the top portion of said spring fastenerand directed toward the bottom portion the spring fastener, the firstbarbs and the second barbs comprising respective first back sections andfirst front sections, the first sections being bent portions of thefirst back sections, and second back sections and second front sections,the second front sections being bent portions of the second backsections.
 24. A spring fastener as defined in claim 3, furthercomprising first barbs and second barbs being cut portions of therespective first and second side of the spring fastener, originatingfrom the vicinity of the top portion of said spring fastener anddirected toward the bottom portion the spring fastener, the first barbsand the second barbs comprising respective first back sections and firstfront sections, the first sections being bent portions of the first backsections, and second back sections and second front sections, the secondfront sections being bent portions of the second back sections.
 25. Aspring fastener as defined in claim 6, further comprising first barbsand second barbs being cut portions of the respective first and secondside of the spring fastener, originating from the vicinity of the topportion of said spring fastener and directed toward the bottom portionthe spring fastener, the first barbs and the second barbs comprisingrespective first back sections and first front sections, the firstsections being bent portions of the first back sections, and second backsections and second front sections, the second front sections being bentportions of the second back sections.
 26. A spring fastener as definedin claim 9, further comprising first barbs and second barbs being cutportions of the respective first and second side of the spring fastener,originating from the vicinity of the top portion of said spring fastenerand directed toward the bottom portion the spring fastener, the firstbarbs and the second barbs comprising respective first back sections andfirst front sections, the first sections being bent portions of thefirst back sections, and second back sections and second front sections,the second front sections being bent portions of the second backsections.
 27. A spring fastener as defined in claim 12, furthercomprising first barbs and second barbs being cut portions of therespective first and second side of the spring fastener, originatingfrom the vicinity of the top portion of said spring fastener anddirected toward the bottom portion the spring fastener, the first barbsand the second barbs comprising respective first back sections and firstfront sections, the first sections being bent portions of the first backsections, and second back sections and second front sections, the secondfront sections being bent portions of the second back sections.
 28. Aspring fastener as defined in claim 15, further comprising first barbsand second barbs being cut portions of the respective first and secondside of the spring fastener, originating from the vicinity of the topportion of said spring fastener and directed toward the bottom portionthe spring fastener, the first barbs and the second barbs comprisingrespective first back sections and first front sections, the firstsections being bent portions of the first back sections, and second backsections and second front sections, the second front sections being bentportions of the second back sections.
 29. A spring fastener as definedin claim 18, further comprising first barbs and second barbs being cutportions of the respective first and second side of the spring fastener,originating from the vicinity of the top portion of said spring fastenerand directed toward the bottom portion the spring fastener, the firstbarbs and the second barbs comprising respective first back sections andfirst front sections, the first sections being bent portions of thefirst back sections, and second back sections and second front sections,the second front sections being bent portions of the second backsections.
 30. A spring fastener as defined in claim 21, furthercomprising first barbs and second barbs being cut portions of therespective first and second side of the spring fastener, originatingfrom the vicinity of the top portion of said spring fastener anddirected toward the bottom portion the spring fastener, the first barbsand the second barbs comprising respective first back sections and firstfront sections, the first sections being bent portions of the first backsections, and second back sections and second front sections, the secondfront sections being bent portions of the second back sections.
 31. Avehicle comprising parts connected with a spring fastener, the springfastener comprising a first side and a second side opposite the firstside, the first side connected to the second side thereby forming aU-shaped structure having a cavity between the first side and the secondside, a bottom portion wherein the first side and the second side areconnected, and a top portion, the first side comprising a first spring,the first spring connected to the first side in the vicinity of thebottom portion, the second side comprising a second spring, the secondspring connected to the second side in the vicinity of the bottomportion, each of the first and second engagement springs comprising apeak, a free end in the vicinity of the top portion, and an engagementregion between the peak and the front end, at least one spring furtherhaving a side-cut section within the engagement region, the side cutsection oriented substantially parallel to the peak and comprising anupper edge and a lower edge.
 32. A vehicle as defined in claim 31,wherein the spring fastener further comprises a hindrance portionbetween the peak and the front end.
 33. A vehicle as defined in claim31, wherein the side-cut section of the spring fastener is disposedwithin the engagement region.
 34. A vehicle as defined in claim 31,wherein the side-cut section of the spring fastener has a triangularshape.
 35. A vehicle as defined in claim 31, wherein the lower edge ofthe side-cut section of the spring fastener is at least partially bentoutwardly.
 36. A vehicle as defined in claim 33, wherein the lower edgeof the side-cut section of the spring fastener is at least partiallybent outwardly.
 37. A vehicle as defined in claim 31, wherein the springfastener further comprises a recess in the vicinity of the top end. 38.A vehicle as defined in claim 33, wherein the fastener further comprisesa recess in the vicinity of the top end.
 39. A vehicle as defined inclaim 36, wherein the spring fastener further comprises a recess in thevicinity of the top end.
 40. A vehicle as defined in claim 32, whereinthe hindrance portion of the fastener further comprises one structureselected from ripple, side rib, upward solid bent extension parallel tothe peak and the recess, knurled region, bent teeth, each having adepth, a bump, and a combination thereof.
 41. A vehicle as defined inclaim 33, wherein the hindrance portion of the fastener furthercomprises one structure selected from ripple, side rib, upward solidbent extension parallel to the peak and the recess, knurled region, bentteeth, each having a depth, a bump, and a combination thereof.
 42. Avehicle as defined in claim 36, wherein the hindrance portion of thefastener further comprises one structure selected from ripple, side rib,upward solid bent extension parallel to the peak and the recess, knurledregion, bent teeth, each having a depth, a bump, and a combinationthereof.
 43. A vehicle as defined in claim 40, wherein the hindranceportion of the fastener further comprises a ripple in the vicinity ofthe peak.
 44. A vehicle as defined in claim 41, wherein the hindranceportion of the fastener further comprises a ripple in the vicinity ofthe peak.
 45. A vehicle as defined in claim 42, wherein the hindranceportion of the fastener further comprises a ripple in the vicinity ofthe peak.
 46. A vehicle as defined in claim 43, wherein the ripple onthe hindrance portion of the fastener has a back side with a curvatureof a gradually decreasing slope.
 47. A vehicle as defined in claim 44,wherein the ripple on the hindrance portion of the fastener has a backside with a curvature of a gradually decreasing slope.
 48. A vehicle asdefined in claim 45, wherein the ripple on the hindrance portion of thefastener has a back side with a curvature of a gradually decreasingslope.
 49. A vehicle as defined in claim 46, wherein the graduallydecreasing slope has the shape of an arc in the range of 50-70 degreeswith a radius in the range of 0.03-0.05 mm.
 50. A vehicle as defined inclaim 47, wherein the gradually decreasing slope has the shape of an arcin the range of 50-70 degrees with a radius in the range of 0.03-0.05mm.
 51. A vehicle as defined in claim 48, wherein the graduallydecreasing slope has the shape of an arc in the range of 50-70 degreeswith a radius in the range of 0.03-0.05 mm.
 52. A vehicle as defined inclaim 31, wherein the fastener further comprises first barbs and secondbarbs being cut portions of the respective first and second side of thespring fastener, originating from the vicinity of the top portion ofsaid spring fastener and directed toward the bottom portion the springfastener, the first barbs and the second barbs comprising respectivefirst back sections and first front sections, the first sections beingbent portions of the first back sections, and second back sections andsecond front sections, the second front sections being bent portions ofthe second back sections.
 53. A vehicle as defined in claim 32, whereinthe fastener further comprises first barbs and second barbs being cutportions of the respective first and second side of the spring fastener,originating from the vicinity of the top portion of said spring fastenerand directed toward the bottom portion the spring fastener, the firstbarbs and the second barbs comprising respective first back sections andfirst front sections, the first sections being bent portions of thefirst back sections, and second back sections and second front sections,the second front sections being bent portions of the second backsections.
 54. A vehicle as defined in claim 33, wherein the fastenerfurther comprises first barbs and second barbs being cut portions of therespective first and second side of the spring fastener, originatingfrom the vicinity of the top portion of said spring fastener anddirected toward the bottom portion the spring fastener, the first barbsand the second barbs comprising respective first back sections and firstfront sections, the first sections being bent portions of the first backsections, and second back sections and second front sections, the secondfront sections being bent portions of the second back sections.
 55. Avehicle as defined in claim 36, wherein the fastener further comprisesfirst barbs and second barbs being cut portions of the respective firstand second side of the spring fastener, originating from the vicinity ofthe top portion of said spring fastener and directed toward the bottomportion the spring fastener, the first barbs and the second barbscomprising respective first back sections and first front sections, thefirst sections being bent portions of the first back sections, andsecond back sections and second front sections, the second frontsections being bent portions of the second back sections.
 56. A vehicleas defined in claim 39, wherein the fastener further comprises firstbarbs and second barbs being cut portions of the respective first andsecond side of the spring fastener, originating from the vicinity of thetop portion of said spring fastener and directed toward the bottomportion the spring fastener, the first barbs and the second barbscomprising respective first back sections and first front sections, thefirst sections being bent portions of the first back sections, andsecond back sections and second front sections, the second frontsections being bent portions of the second back sections.
 57. A vehicleas defined in claim 42, wherein the fastener further comprises firstbarbs and second barbs being cut portions of the respective first andsecond side of the spring fastener, originating from the vicinity of thetop portion of said spring fastener and directed toward the bottomportion the spring fastener, the first barbs and the second barbscomprising respective first back sections and first front sections, thefirst sections being bent portions of the first back sections, andsecond back sections and second front sections, the second frontsections being bent portions of the second back sections.
 58. A vehicleas defined in claim 45, wherein the fastener further comprises firstbarbs and second barbs being cut portions of the respective first andsecond side of the spring fastener, originating from the vicinity of thetop portion of said spring fastener and directed toward the bottomportion the spring fastener, the first barbs and the second barbscomprising respective first back sections and first front sections, thefirst sections being bent portions of the first back sections, andsecond back sections and second front sections, the second frontsections being bent portions of the second back sections.
 59. A vehicleas defined in claim 48, wherein the fastener further comprises firstbarbs and second barbs being cut portions of the respective first andsecond side of the spring fastener, originating from the vicinity of thetop portion of said spring fastener and directed toward the bottomportion the spring fastener, the first barbs and the second barbscomprising respective first back sections and first front sections, thefirst sections being bent portions of the first back sections, andsecond back sections and second front sections, the second frontsections being bent portions of the second back sections.
 60. A vehicleas defined in claim 51, wherein the fastener further comprises firstbarbs and second barbs being cut portions of the respective first andsecond side of the spring fastener, originating from the vicinity of thetop portion of said spring fastener and directed toward the bottomportion the spring fastener, the first barbs and the second barbscomprising respective first back sections and first front sections, thefirst sections being bent portions of the first back sections, andsecond back sections and second front sections, the second frontsections being bent portions of the second back sections.
 61. A vehicleas defined in claim 31, wherein the spring fastener further comprises anelastic body molded at least under the lower side of the head of thefastener.
 62. A vehicle as defined in claim 36, wherein the springfastener further comprises an elastic body molded at least under thelower side of the head of the fastener.
 63. A vehicle as defined inclaim 31, wherein the spring fastener further comprises: a casingsurrounding at least partially the lower section of the U-shapedstructure, except at least the free end of each spring, the casingenclosing the cavity within the first side and the second side of saidU-shaped structure; and an elastic body comprised of at least a gasket,the gasket extending away from the closed cavity in the vicinity of thetop of the U-shaped structure; wherein the casing is substantiallynon-elastic.
 64. A vehicle as defined in claim 36, wherein the springfastener further comprises: a casing surrounding at least partially thelower section of the U-shaped structure, except at least the free end ofeach spring, the casing enclosing the cavity within the first side andthe second side of said U-shaped structure; and an elastic bodycomprised of at least a gasket, the gasket extending away from theclosed cavity in the vicinity of the top of the U-shaped structure;wherein the casing is substantially non-elastic.
 65. An assembly of afirst part comprising a rib and a spring fastener, the spring fastenercomprising a first side and a second side opposite the first side, thefirst side connected to the second side thereby forming a U-shapedstructure having a cavity between the first side and the second side, abottom portion wherein the first side and the second side are connected,and a top portion, the first side comprising a first spring, the firstspring connected to the first side in the vicinity of the bottomportion, the second side comprising a second spring, the second springconnected to the second side in the vicinity of the bottom portion, eachof the first and second engagement springs comprising a peak, a free endin the vicinity of the top portion, and an engagement region between thepeak and the front end, at least one spring further having a side-cutsection within the engagement region, the side cut section orientedsubstantially parallel to the peak and comprising an upper edge and alower edge, wherein the rib of the first part is inserted into thecavity of the spring fastener.
 66. An assembly as defined in claim 65,wherein the lower edge of the side-cut section of the spring fastener isat least partially bent outwardly.
 67. An assembly as defined in claim65, wherein the spring fastener further comprises an elastic body moldedat least under the lower side of the head of the fastener.
 68. Anassembly as defined in claim 66, wherein the spring fastener furthercomprises an elastic body molded at least under the lower side of thehead of the fastener.
 69. An assembly as defined in claim 65, whereinthe spring fastener further comprises: a casing surrounding at leastpartially the lower section of the U-shaped structure, except at leastthe free end of each spring, the casing enclosing the cavity within thefirst side and the second side of said U-shaped structure; and anelastic body comprised of at least a gasket, the gasket extending awayfrom the closed cavity in the vicinity of the top of the U-shapedstructure; wherein the casing is substantially non-elastic.
 70. Avehicle as defined in claim 66, wherein the spring fastener furthercomprises: a casing surrounding at least partially the lower section ofthe U-shaped structure, except at least the free end of each spring, thecasing enclosing the cavity within the first side and the second side ofsaid U-shaped structure; and an elastic body comprised of at least agasket, the gasket extending away from the closed cavity in the vicinityof the top of the U-shaped structure; wherein the casing issubstantially non-elastic.
 71. An assembly of a second part comprising aslot and a spring fastener, the spring fastener comprising a first sideand a second side opposite the first side, the first side connected tothe second side thereby forming a U-shaped structure having a cavitybetween the first side and the second side, a bottom portion wherein thefirst side and the second side are connected, and a top portion, thefirst side comprising a first spring, the first spring connected to thefirst side in the vicinity of the bottom portion, the second sidecomprising a second spring, the second spring connected to the secondside in the vicinity of the bottom portion, each of the first and secondengagement springs comprising a peak, a free end in the vicinity of thetop portion, and an engagement region between the peak and the frontend, at least one spring further having a side-cut section within theengagement region, the side cut section oriented substantially parallelto the peak and comprising an upper edge and a lower edge, wherein thespring fastener is disposed within the slot of the second part
 72. Anassembly as defined in claim 71, wherein the lower edge of the side-cutsection of the spring fastener is at least partially bent outwardly. 73.An assembly as defined in claim 71, wherein the spring fastener furthercomprises an elastic body molded at least under the lower side of thehead of the fastener.
 74. An assembly as defined in claim 72, whereinthe spring fastener further comprises an elastic body molded at leastunder the lower side of the head of the fastener.
 75. An assembly asdefined in claim 71, wherein the spring fastener further comprises: acasing surrounding at least partially the lower section of the U-shapedstructure, except at least the free end of each spring, the casingenclosing the cavity within the first side and the second side of saidU-shaped structure; and an elastic body comprised of at least a gasket,the gasket extending away from the closed cavity in the vicinity of thetop of the U-shaped structure; wherein the casing is substantiallynon-elastic.
 76. A vehicle as defined in claim 72, wherein the springfastener further comprises: a casing surrounding at least partially thelower section of the U-shaped structure, except at least the free end ofeach spring, the casing enclosing the cavity within the first side andthe second side of said U-shaped structure; and an elastic bodycomprised of at least a gasket, the gasket extending away from theclosed cavity in the vicinity of the top of the U-shaped structure;wherein the casing is substantially non-elastic.
 77. A spring fasteneras defined in claim 1, further comprising an elastic body molded atleast under the lower side of the head of the fastener.
 78. A springfastener as defined in claim 6, further comprising an elastic bodymolded at least under the lower side of the head of the fastener.
 79. Aspring fastener as defined in claim 1, further comprising: a casingsurrounding at least partially the lower section of the U-shapedstructure, except at least the free end of each spring, the casingenclosing the cavity within the first side and the second side of saidU-shaped structure; and an elastic body comprised of at least a gasket,the gasket extending away from the closed cavity in the vicinity of thetop of the U-shaped structure; wherein the casing is substantiallynon-elastic.
 80. A spring fastener as defined in claim 6, furthercomprising: a casing surrounding at least partially the lower section ofthe U-shaped structure, except at least the free end of each spring, thecasing enclosing the cavity within the first side and the second side ofsaid U-shaped structure; and an elastic body comprised of at least agasket, the gasket extending away from the closed cavity in the vicinityof the top of the U-shaped structure; wherein the casing issubstantially non-elastic.